The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 2002
Filed:
Sep. 20, 2000
Keith Bryan Hardin, Lexington, KY (US);
Robert Aaron Oglesbee, Lexington, KY (US);
Lexmark International, Inc., Lexington, KY (US);
Abstract
A segmented spectrum clock generator is provided that exhibits a frequency response having multiple segments that with a sharp rolloff on both sides of each individual segment's peak amplitude across the entire frequency spectrum. In order to meet proposed new CISPR-22 rules, each segment must roll off by at least 10 dB at adjacent frequencies that are ±150 kHz on both sides of (or offset from) each of the peaks. The segmented spectrum clock generator output signal is generated by a frequency synthesizer circuit that modulates the output frequency at a predetermined rate between a “lower bound” and an “upper bound” of modulation frequencies. Moreover, the modulation of the output frequencies is controlled so as to form a “segmented sperm” frequency domain output that has rather distinct peaks and valleys, and whose modulation profile has a graphical appearance of frequency vs. time that is somewhat “peaky,” although many other profile shapes could instead be used.